1. Field of the Technology
The present invention relates to image processing technology, and more particularly to an image processing method for multi-depth-of-field 3D-display, which divides an image into a foreground and a background to be displayed by a front panel and a back panel respectively, presents a 3D impression by a distance between the front panel and the back panel, and provides signals to the front panel and the back panel simultaneously to achieve a synchronous display.
2. Background of the Invention
The displays are always the most frequently used electronic product for people, and advances of the display also indicate that humans are pursuing more real visual experience. From early black-and-white TV to color TV, and current high definition TV, all of which are pursuing more natural, more real image quality. The development of 3D-display also provides people with further visual senses, and further provides perception of 3D space in addition to common images and colors. The human brain may utilize binocular parallax to determine the sense of distance of object. These 3D feelings can provide people with greater reliability when determining image information, and therefore, with the vigorous development of display technology, the application of 3D image display is increasingly diverse.
Generally speaking, a 3D-display must be provided with characteristics including binocular parallax and motion parallax. The so called binocular parallax refers to a displacement of about 6.5 centimeters (statistic of Europeans) in the horizontal direction of left eye and right eye of an observer, such that when watching an object, the received contents of image are slightly different due to small differences between observing angles. The motion parallax means that when the locations of eyes of the observer move, the observing angles change accordingly, and the contents received by eyes are thus different. So if we hope to receive a 3D image, we should make the left eye and the right eye to receive individual images with slight difference.
FIGS. 1a and 1b are schematic views representing fusion along a depth direction and continuous depth variation when the front panel and the back panel are playing images with different brightness respectively according to the prior art. The 3D impression of the image to an observer is generated by the distance between the front panel D1 (adjacent to the observer) and the back panel D2 (away from the observer) and the two images with different brilliances on the front panel and the back panel respectively and the binocular parallax. With this principle, the Japanese NTT company provides a method of utilizing two overlapping liquid crystal panels to display two images with the same size, such that the images of the front and back objects are overlapped by utilizing the different distances of the objects away from the observer and the differences of darkness and color, so as to present the 3D impression to the observer. However, the method has the disadvantages such as the difficulty of aligning the front panel and the back panel, and moreover, due to the overlapping of two 2D images, the 3D impression is preferred only when observing from a front direction but not obvious at other observing angles.
FIGS. 2a and 2b are schematic views representing a first image processing method and a second image processing method in the prior art respectively. As for image processing of two (or more) panels described above, the image signals corresponding to each panel must be provided, and the commonly used method (disclosed in pure depth limited) is utilizing a display card with two outputs (the first image processing method as shown in FIG. 2a) and utilizing two computers or play devices (the second image processing method as shown in FIG. 2b).
The first image processing method requires the computer C1 to be provided with special software S1, so that the display card B1 is able to output the corresponding image signals to the front panel D1 and the back panel D2 simultaneously, achieving the effect of synchronous output. While the second image processing method requires two computers C1, C2 or play devices (not shown), and utilizes other communication interface (not shown) or another console (C3) responsible for controlling to command the two computers C1, C2 to play synchronously.
However, the two image processing methods both require computers with special specification for synchronous control of the image output, otherwise, it is difficult to synchronize the signals provided to the front panel and the back panel, and they are unable to be used by the play device (such as DVD, cable TV, and PS3) used in common families.
In view of the problems described above, an image processing method is provided for multi-depth-of-field 3D-display, so as to overcome the defects of the conventional technologies.